Search

We report a case of a 73-year-old male with rheumatoid arthritis presenting with acute abdominal and back pain and rapidly developing multiorgan failure. A positive blood culture (Staphylococcus aureus, Candida species) followed by transoesophageal sonography established a diagnosis of mitral valve infective endocarditis. At the autopsy, the heart examination revealed fibrinous pericarditis and multiple small vegetations on the mitral valve. The mitral valve itself showed no significant damage. Surprisingly, the histological examination of the mitral valve showed granulomatous inflammation with central fibrinoid necrosis and peripheral palisade of histiocytes, with occasional giant cells and lymphocytic inflammatory infiltrate - findings consistent with a rheumatoid nodule. Infective vegetations were overlying the nodule. Due to its relative frequency, a possibility of cardiac involvement by rheumatoid arthritis and its potential infective complications should be considered in patients with appropriate history and clinical symptoms.

Complex laboratory investigation is necessary for the diagnosis and relevant classification of lymphomas. The classical histopathological morphology and cytology investigation is essential, but further investigations such as immunohistochemistry and fluorescence in situ hybridization are necessary. It is also important to employ flow cytometry as a method of investigation running synchronously or preceding the histopathological approach. Last but not least, the investigation of nucleic acids in lymphoma by molecular approaches is necessary and has become an everyday practice. Communication between pathologists and clinical colleagues (oncologists, hematologists, internal medicine specialists and radiologists) is very important. We demonstrate the necessity of a complex diagnostic approach to lymphomas and an appropriate interpretation of all laboratory investigations giving examples of eight patients with various types of lymphomas. In some cases, it is impossible to properly diagnose a lymphoma without molecular investigation. Occasionally, the results of the molecular investigation may be misleading and/or may be inaccurately interpreted, leading to an incorrect conclusion. For that reason, it is very important to incorporate all specialized laboratories and their teams under one roof (preferably that of pathology departments), enabling tight and daily cooperation between the specialists. This is the way to reach a precise diagnosis in a majority of cases, as well as how to comply with clinical expectations of properly classified lymphomas for a targeted therapy of patients.

Histiocytic necrotizing lymphadenitis / Kikuchi-Fujimoto disease (HNL/K-F) is being recognized with an increasing frequency not only in the East Asia but also on the American continents and in the Europe. Still the diagnostics of HNL/K-F is not easy and difficulties with its proper classification persist. In a group of 19 patients diagnosed primarily or as consults at our department there were 12 woman and 7 men. An average age at diagnosis was 28 years, median 25 years. Cervical lymph nodes were involved in 18 patients. Bilateral lymphadenopathy was present in one patient, the remaining 17 were unilateral. Inguinal lymph node was affected in one patient. In one other patient there were enlarged retroperitoneal lymph nodes simultaneously with a cervical lymphadenopathy. The size of the lymph nodes varied between 5 mm to 32 mm. The subclassification showed the necrotizing type in 14 patients, in one there was a predominant xanthomatous tissue reaction around the necrotic areas (xanthomatous type), and in 4 patients the disease was recognized as the proliferative type without necrosis (in two with a variously intense apoptosis of the proliferating lymphocytes). Of 10 consult cases the tumor was primarily evaluated as B cell lymphoma not otherwise specified (1x), peripheral T cell lymphoma (1x), classical Hodgkin lymphoma of mixed cellularity (1x); two patients were submitted with a differential diagnosis between peripheral T cell lymphoma and HNL/K-F; in one diagnosis of probable EBV lymphadenitis and in one diagnosis HNL/K-F was made. There were no data submitted in the remaining three cases. The authors stress diagnostic features which should lead to the diagnosis of the disease and should prevent unnecessary oncological staging investigations and potential chemotherapy for a lymphoma. Among diagnostic features of HNL/K-F identification of the proliferating cells - CD8 activated lymphocytes with apoptotic decay prevail, there are frequent plasmacytoid monocytes and a striking reaction of macrophages which are CD68/myeloperoxidase positive. There are virtually no neutrophil granulocytes and there is a miminal participation of plasma cells. In case of necrotizing and xanthomatous type infectious causes are to be ruled out as well. In case we still need to distinguish HNL/K-F from a lymphoma PCR analysis of a rearrangement of the immunoreceptor gene in T cell population should be investigated.

We studied monoclonality of tumour cells by polymerase chain reaction (PCR) in paediatric lymphomas. In B-lymphomas we detected monoclonal rearrangement of the immunoglobulin of the T-cell receptor delta and gamma chain (TCR, TCR-delta, TCR-gamma) by an analogous way. We examined a group of 37 paediatric patients with lymphomas (26 with B-lymphomas and 11 with T-lymphomas). Monoclonal gene rearrangement was found in 34 cases, i.e. the method used in this study proved to be successful in 92% of cases. We confirmed our results by correlation with histologic and immunohistologic diagnoses. The method may be used as a complementary diagnostic tool in differential diagnosis of lymphoma versus non-neoplastic proliferation of lymphatic tissue, in distinction between B- and T-lymphomas, and to separate lymphomas and other malignancies. Beside the pure diagnostic usage we perceive the main importance of the method in monitoring minimal residual disease (MRD), because amplified products of PCR may be sequenced and used for preparing tumour specific primers and probes.

Tumors of the sympathetic nervous system (NT), namely neuroblastoma (NB) and ganglioneuroblastoma (GNB), have a variable clinical course. Prognostic factors include clinical stage, age of the patient, histological grade, and changes at the genomic level, of which amplification of N-myc oncogene is a well recognized phenomenon. The aim of this study was to establish the status of the N-myc oncogene in NT and to compare the results with histopathological grading, with risk groups according to criteria outlined by Joshi et al., and with the clinical stage. To detect the amplification of N-myc oncogene we used differential polymerase chain reaction (D-PCR). Amplified N-myc oncogene was found in 10 out of 31 investigated children with NB (32%). The result of D-PCR could not be interpreted reliably in two patients. Of seven children with GNB the N-myc amplification was found in one case. None of seven children with ganglioneuroma was found to have amplified N-myc oncogene. The tumors with N-myc amplification were histologically poorly differentiated of undifferentiated with a high mitotic activity-8 children were classified as a high risk category; in two we had not enough surgical material to evaluate the histological prognostic factors. The correlation of N-myc status with clinical stage revealed N-myc amplification in two of 9 children classified as clinical stage III, and in eight of 11 children classified as clinical stage IV. The N-myc amplification was not found in any child diagnosed at stage I, II and IV. Five of 10 children with NB and N-myc amplification died of the disease progression. Four children died in the group of 19 children without N-myc amplification. The median of follow-up was 18 months. The patient with GNB and N-myc amplification also died of the disease progression. Although the follow-up period of the investigated group of patients was short, the results showed that the amplification of N-myc oncogene was associated with tumors of patients diagnosed at a late clinical stage (III and IV), and with tumors whose morphology and age were assessed collectively under the term "high risk group".